When the binding machine is working, binding holes are punched on paper at first, and then binding clips (binding rings) are pressed into the paper binding holes to finish binding. For example, a Chinese Patent with the publication No. CN102653194A and publication date Sep. 5, 2012 discloses a binding machine, comprising a stand, a punching structure mounted on the said stand and a transmission mechanism, wherein, the said punching structure comprises a first punching member provided with a plurality of first punching blades, a second punching member provided with a plurality of second punching blades, and a switching mechanism enabling the first punching member and the second punching member to be respectively separated and reunited with the transmission mechanism. The binding machine provided by the invention is provided with two punching blades capable of punching two holes so as to meet the requirement of different customers. However, the existing binding machine is only applicable to one binding clip, has to be changed when diameter of the binding clips is changed, and has poor applicability.